103 A Bifurcation Model Predicts Intravascular Catheter Herniation When Using Transradial Access in Neuroendovascular Procedures

Abstract

INTRODUCTION: The speed and safety of acute ischemic stroke interventions can be improved with catheter-based revascularization performed via the transradial access versus the traditional transfemoral access. A critical source of delay and procedural failure is a phenomenon known as herniation where the catheter system suddenly buckles and deviates from the intended endovascular pathway as the surgeon attempts to track one device over or through another around a tight bend. METHODS: Recent modeling work suggests that herniation is associated with a bifurcation in strain energy. We hypothesized that herniation could be predicted by modeling the strain energy stored in a catheter based on its flexural rigidity and the vascular anatomy. To test our hypothesis, we developed a computational model using finite element analysis and an experimental benchtop model using 3D-printed patient-specific aortic arches. Our mathematical model was validated in vivo using observational data derived from patient and porcine endovascular surgeries. RESULTS: Vascular geometry and flexural rigidity were used to derive the bifurcation condition and predict catheter stability versus instability (herniation). Catheter instability criterion was predictive of herniation in our computational model (sensitivity 100.0%, PPV 93.5%, NPV 100.0%); experimental ex vivo model (sensitivity 92.3%, PPV 89.6%, NPV 90.0%); patient in vivo model (sensitivity 100.0%, PPV 80.0%, NPV 100.0%); and porcine in vivo model (sensitivity 100%, PPV 100%, NPV 100%). CONCLUSIONS: We validated a predictive model of catheter herniation based upon the hypothesis that bifurcation in strain energy drive the phenomenon. Key factors in the model are the curvature of the vascular pathway and the flexural rigidity of the coaxial devices. Results suggest that strategic selection of catheters and wires based on their known flexural rigidity can be used to prevent the bifurcation in strain energy that causes herniation.